Signal translating apparatus



July 12, 1938. v F, M ss 2,123,633

SIGNAL TBANSLATING APPARATUS Filed Dec. 31, 1936 III/I IIIIIIIIIIIihwentor Mas-5a;

dimmed Patented July 12, 1938 5 UNITED STTES PATENT orrics SIGNALTRANSLATING APPARATUS Frank Massa, West Collingswood, N. J., assig'norto Radio Corporation of America,

tion of Delaware Application December 31, 1936, Serial No. 118,634

10 Claims.

Both driving units, including their separate voice coils and theircommon field coil, are housed entirely within the horn structure, andthe leads from the several coils must, obviously, be brought out in someway to permit making connection thereto.

The primary object of my presentinvention is to provide an improvedmeans whereby connection may be conveniently made to the several coilsof a horn loudspeaker system of the type described.

More specifically, it is an object of my invention to so arrange theleads of the field and voice coils of horn loudspeakers generally thatexternal connection thereto may be readily made.

Another object of my invention is to provide an improved arrangement ofthe type set forth which will in no way impair the efficiency of theloudspeaker system.

It is also an object of my invention to provide an improved arrangementas aforesaid which is simple and durable in construction, which canreadily be installed by'even an unskilled worker, and which is efiicientin use.

In accordance with my present invention, I connect the leads of bothvoice coils and the field coil to terminal elements on an insulatedblock or strip mounted on the outer periphery of the frame member of oneof the diaphragms, preferably the large, low frequency diaphragm. Flexible leads connect the terminal elements on the insulated strip withsuitable plugs or binding posts on the back of the large horn, and theseveral coils may be connected to external circuits by means of theseplugs or binding posts.

The novel features that I consider characteristic'of my invention areset forth with particularity in the appended claims. The inventionitself, however, together with additional-objects and advantagesthereof, will best be understood fromthe following description of oneembodiment thereof, when read in connection with the accompanyingdrawing, in which Figure 1 is a view partlyv in plan and partly insection showing the arrangement of the driving 7 units within a compoundhorn loudspeaker of the type previously described, and illustrating,also, one way of bringing out the several coil leads according to mypresent invention, and

Figure 2 is a fragmentary rear elevation of the loudspeaker assemblyshowing the input connections therefor and the coupling leads betweensaid input connections and the terminal elements on the insulated block.

Referring more specifically to the drawing,

wherein similar reference characters indicate corresponding partsthroughout, there is shown a compound horn loudspeaker of the typedisclosed in my aforementioned copending application and comprising afolded, low frequency horn l and one or more straight-axis highfrequency horns 3. The horn I is fed by a relatively largefrusto-conical diaphragm or other suitable vibratile member 5 on thevoice coil form of which is wound a voice coil 1, while the small horns3 are fed by a small frusto-conical diaphragm 9 carrying a voice coil Hthereon, the magnetic field in which the voice coils l and ll operatebeing supplied by a single field coil l3, as more fully disclosed in mysaid copending application. Preferably, the driving unit for the horn iis designed to particularly reproduce the lower frequencies within theaudio frequency range, while the driving unit for the horns 3 isdesigned to particularly reproduce the higherv frequencies within thisrange, whereby the entire loudspeaker system is adapted to efficientlyreproduce sounds over a wide range.

-As will be clearly seen from Fig. 1, the two electrodynamic drivingunits described are housed entirely within the large horn, l, and inorder to connect the voice coils l and H and the field coil l3 tosuitable external circuits, it is necessary to bring out the leads fromthe several coils to points which are easily accessible from outside thehorn structure. For this purpose, use may advantageously be made of theframe or supporting structure which supports either of the diaphragms5-01" 9, and by way of illustration, I have selected the supportingframe for, the large diaphragm 5.

The diaphragm 5 is clamped at its periphery between a ring l5 and theflange I! of a suitable metallic supporting frame l9, such as theconventional dish-pan, the'flange I! being of larger diameter than thediaphragm 5 so that and the coils I, 9 and [3 being located to the rearof the flange H, as viewed in Fig. 2. The

terminal strip 23 is provided with several sets of terminal elements 25,such as metallic pins, which extend therethrough and which are, ofcourse, electrically insulated from each other, since they are mountedon the insulated strip 23 in spaced relation, the pins 25 serving asterminal elements for the several coil leads Thus, the leads 2'! fromthe Voice coil 1 may be directly connected to one set of pins 25 and theleads 29 from the field coil l3 may be directly connected to another setof pins 25, as clearly shown in Fig. l, and the leads 3| from the voicecoil ll may also be directly connected to the third set of pins 25, ifdesired. In some cases, however, it may not be convenient to connect theleads 3ldirectly to a set of pins 25,'and in such cases, the leads 3|may be connected to one end of a set of pins 33 or the like on aninsulated strip 35 which is carried by the supporting structure 31 forthe diaphragm 9, and the opposite ends of the pins 33 connected to thethird set of terminal pins 25 by a pair of leads 39.

The horn I is provided with an opening 4| in its rear wall through whichthe electrodynamic driving units heretofore described may be insertedprior to being mounted therein, and a cover plate 43 is secured to thehorn I over the opening 4!. Mounted on the cover plate 43 are three setsof suitable input terminals by means of which suitable external circuitsmay be connected to the several coils of the loudspeaker. These inputterminals may, for example, comprise a pair of binding posts 45 markedLow which are connected by a pair of leads 41 to the pins 25 havingconnection with the voice coil I, a second pair of binding posts 49marked High and connected by a pair of leads to the pins 25 havingconnection with the voice coil H, and a plug 53 marked Field, which isconnected by a pair of leads 55 to the pins 25 having connection withthe field coil I3. The binding posts 45 and 49 and the plug 53 thusconstitute convenient means for easily making connection to the voicecoils 1 and H and the field coil 13.

Although I have shown and described but one embodiment of my invention,it'will be readily apparent to those skilled in the art that many othermodifications thereof are possible. For example, the supporting frame I9may itself be formed of insulating material, in which case the insulatedstrip 23 may be dispensed with. Also, if desired, the leads from theseveral coils may all be connected to terminal elements on the insulatedstrip 35 instead of the strip 23, and the input terminals 45, 49 and 53may be mounted on the side, bottom or top of the horn I instead of onthe back wall thereof, or in any other suitable location thereon. Manyother changes will, no doubt, also readily suggest themselves and Itherefore desire that my invention shall not be limited except insofaras is made necessary by the prior art and by the spirit of the appendedclaims. a

I claim as my invention:

the peripheral edge of said diaphragm, an insulated terminal stripmounted on said flange,

electrically conductive terminal elements fixed to said strip inelectrically insulated relation, a voice coil carried by said diaphragm,and a field coil associated with said voice coil, said voice coil andsaid field coil each having leads connected to said terminal elements.

2. In an electrodynamic loudspeaker, the combination of a diaphragm, ametallic frame supporting said diaphragm at its periphery, said framebeing of greater diameter than said diaphragm whereby to provide anannular flange beyond the peripheral edge of said diaphragm, said flangehaving a plurality of openings therein, an insulated terminal stripmounted on said flange over said openings, electrically conductiveterminal elements fixed to said strip in electrically insulatedrelation, said elements passing through said openings, a voice coilcarried by said diaphragm, and a field coil associated with said voicecoil, said voice coil and said field coil each having leads connected tosaid terminal elements.

3. The invention set forth in claim 2 characterized in that said coilsare located on one side of said flange and said terminal strip islocated on the opposite side of said flange, and characterized furtherin that said terminal elements extend through said strip wherebyconnection may be made thereto on either side of said flange.

4. The invention set forth in claim 2 characterized in that said coilsare located at the rear of said flange and said terminal strip ismounted on the front of said flange, characterized further in that saidterminal elements extend through said strip, and characterized stillfurther in that said leads are connected to the rear ends of saidterminal elements.

5. The invention set forth in claim 2 characterized by the addition of ahousing in which the structure set forth in claim 2 is housed, and. aplurality of input terminals on said housing, said terminal elementsbeing connected to said input terminals.

6. The invention set forth in claim 2 characterized by the addition of ahousing in which the structure set forth in claim 2 is housed, and aplurality of input terminals on said housing, characterized further inthat saidcoils are located on one side of said flange and said terminalstrip is located on the opposite side of said flange, and characterizedstill further in that said terminal elements extend through said strip,said coil leads being connected to the adjacent ends of said terminalelements, and the opposite ends of said terminal elements beingconnected to said input terminals. I

7. In a loudspeaker system, a plurality of electrodynamic units eachhaving a diaphragm and each diaphragm being'provided with a voice coil,a single field coil common to all of said units, separate supportingdevices for independently supporting each of said diaphragms, and aterminal strip on one of said supporting devices, each of said voicecoils and said field coil having leads connected to said terminal strip.

8. In a compound horn loudspeaker, a pair of horns, a pair of drivingunits each including a diaphragm and an associated voice coil, one ofsaid units being arranged to feed into one of said horns and the otherof said units being arranged to feed into the other of said horns, asingle field coil common to both of said units, separate supportingdevices for independently supporting each of said diaphragms, aninsulated terminal strip on only one of said supporting devices, andterminal elements carried by said strip in electrically insulatedrelation, said voice coils and said field coil all having leadsconnected to said terminal elements.

9. The invention set forth in claim 8 characterized in that one of saidunits is relatively large and particularly adapted to reproduce lowfrequencies, While the other of said units is relatively small andparticularly adapted to reproduce high frequencies, and characterizedfurther in that said insulated strip is mounted on the diaphragmsupporting device of said large unit.

10. The invention set forth in claim 8 characterized in that said unitsare housed entirely within one of said horns, and characterized furtherby the addition of a plurality of input terminals on said horn, saidterminal elements being connected to said input terminals.

FRANK MASSA.

